'POT' issues with long cable

[Sphere]

Why not use a pressure switch like the kind you find in a washing machine, you can use the switch to turn the pumps on and once the required pressure is reached the pumps will cut off.

Sphere.

[Darrel Taylor]

Hmmm, yup pressure works good too.

12 Ft/head = ~5 PSI if I remember right?

Maybe an MPX???? (tube version) with some scalerobotics code.
Feet of head, instead of altitude. ??

Altimeter : up to 16 bit altimeter solution
http://sites.picbasic.net/component/...,91/pageid,81/


MPX4115A Datasheet (up to 16 PSI)
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[Byte_Butcher]

I was looking at pressure transducer options too.
Like these...
http://search.digikey.com/scripts/Dk...ame=MSP6800-ND

But they're just as pricey as the "Ping" and I wonder how well they would like water inside them.



steve

[aratti]

I wonder how well they would like water inside them

Generally air pressure sensor hate water. But in this case the sensor can be located far away from water tank. All you need is a tube (the larger it is the best resolution you get) with the top end sealled and connected via a small plastic tube to your sensor. The open side of the tube is deeped into water so that if the level increase the space, inside the immersed tube will decrease and as a conseguence the air pressure will increase. The only problem with this method is that Pressure = volume * temperature (gas equation). So if temperature double also the pressure inside the tube will double without any change in water level. This to warn you to use also a temperature sensor and compensate the pressure reading for the temperature change.

Al.

[Archangel]

There is another downside to the air filled tube with a pressure sensor. The water will absorb the air and you will have a water filled tube. Now a sealed bladder would work.